Bottom Line:
A novel VN/C nanostructure consisting of VN nanoparticles and graphite-dominant carbon layers is synthesized by nitridation of V2O5 using melamine as reductant under inert atmosphere.Moreover, the electrocatalytic performance of VN/C towards oxygen reduction reaction (ORR) in alkaline electrolyte is fascinating.The results show that VN/C has a considerable ORR activity, including a 75 percent value of the diffusion-limited current density and a 0.11 V smaller value about the onset potential with respect to Pt/C catalyst.

Affiliation: State Key Laboratory of Information Photonics and Optical Communications &School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China.

ABSTRACTA novel VN/C nanostructure consisting of VN nanoparticles and graphite-dominant carbon layers is synthesized by nitridation of V2O5 using melamine as reductant under inert atmosphere. High crystalline VN nanoparticles are observed to be uniformly distributed in carbon layers with an average size of ca13.45 nm. Moreover, the electrocatalytic performance of VN/C towards oxygen reduction reaction (ORR) in alkaline electrolyte is fascinating. The results show that VN/C has a considerable ORR activity, including a 75 percent value of the diffusion-limited current density and a 0.11 V smaller value about the onset potential with respect to Pt/C catalyst. Moreover, the excellent methanol-tolerance performance of VN/C has also been verified with 3 M methanol. Combined with the competitive prices, this VN/C nanocomposite can serve as an appropriate non-precious methanol-tolerant ORR catalyst for alkaline fuel cells.

Mentions:
In order to reveal the physical morphology of VN visually, TEM images at different magnifications and element mapping spectra were displayed in Fig. 2 and Fig. 3. Surprisingly, as-prepared VN sample is found out to be a kind of composite consisting of nanoparticles and surrounding layers which is very similar to the structure of metal oxides nanoparticles supported on graphene sheets. Although the average size of nanoparticles (ca 13.45 nm, see Fig. S1) matches well with the results calculated from XRD analysis, the existence of surrounding layers seems to be contradictory. Considering the synthesis condition and process: the pyrolysis of melamine will release NH3 and some chemically reactive hydrogen-, carbon-, and nitrogen-containing atomic species at higher temperatures30, it is believed that the surrounding layers are composed of carbon layers which may grow by a self-catalytic process by VN nanocrystals as reported by Yao et al31 and exhibit no obvious diffraction peaks due to the destroyed regular stacks of carbon layers32.

Mentions:
In order to reveal the physical morphology of VN visually, TEM images at different magnifications and element mapping spectra were displayed in Fig. 2 and Fig. 3. Surprisingly, as-prepared VN sample is found out to be a kind of composite consisting of nanoparticles and surrounding layers which is very similar to the structure of metal oxides nanoparticles supported on graphene sheets. Although the average size of nanoparticles (ca 13.45 nm, see Fig. S1) matches well with the results calculated from XRD analysis, the existence of surrounding layers seems to be contradictory. Considering the synthesis condition and process: the pyrolysis of melamine will release NH3 and some chemically reactive hydrogen-, carbon-, and nitrogen-containing atomic species at higher temperatures30, it is believed that the surrounding layers are composed of carbon layers which may grow by a self-catalytic process by VN nanocrystals as reported by Yao et al31 and exhibit no obvious diffraction peaks due to the destroyed regular stacks of carbon layers32.

Bottom Line:
A novel VN/C nanostructure consisting of VN nanoparticles and graphite-dominant carbon layers is synthesized by nitridation of V2O5 using melamine as reductant under inert atmosphere.Moreover, the electrocatalytic performance of VN/C towards oxygen reduction reaction (ORR) in alkaline electrolyte is fascinating.The results show that VN/C has a considerable ORR activity, including a 75 percent value of the diffusion-limited current density and a 0.11 V smaller value about the onset potential with respect to Pt/C catalyst.

Affiliation:
State Key Laboratory of Information Photonics and Optical Communications &School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China.

ABSTRACTA novel VN/C nanostructure consisting of VN nanoparticles and graphite-dominant carbon layers is synthesized by nitridation of V2O5 using melamine as reductant under inert atmosphere. High crystalline VN nanoparticles are observed to be uniformly distributed in carbon layers with an average size of ca13.45 nm. Moreover, the electrocatalytic performance of VN/C towards oxygen reduction reaction (ORR) in alkaline electrolyte is fascinating. The results show that VN/C has a considerable ORR activity, including a 75 percent value of the diffusion-limited current density and a 0.11 V smaller value about the onset potential with respect to Pt/C catalyst. Moreover, the excellent methanol-tolerance performance of VN/C has also been verified with 3 M methanol. Combined with the competitive prices, this VN/C nanocomposite can serve as an appropriate non-precious methanol-tolerant ORR catalyst for alkaline fuel cells.